Recovering phosphorus from corn ethanol waste

About 40% of the corn produced in the U.S. is used to make bioethanol. When industrial plants process corn grains to make the fuel, or even food products such as corn syrup, they generate by-products containing high levels of phosphorus, some of which end up flowing to wastewater treatment plants. Nutrients such as phosphorus and nitrogen leave these treatment plants and enter waterways, eventually flowing to bodies of water, such as the Gulf of Mexico, where they contribute to the growth of low-oxygen dead zones. Roland D. Cusick of the University of Illinois, Urbana-Champaign, and colleagues looked for economical and sustainable ways to recover the phosphorus from the by-products at corn-processing plants. At the meeting, one of Cusick’s students, Navneet Sharma, described experiments the team performed on different types of processed corn by-products. The researchers found they could precipitate organic and inorganic phosphorus compounds in minutes from the material by adding calcium and tweaking the solution’s pH. Cusick says the team must next analyze the value of the recovered phosphorus compounds and whether they can be used as fertilizer or as supplements for animal feed.